source:
sasview/src/sas/perspectives/calculator/media/sld_calculator_help.rst
@
24d3a40
Last change on this file since 24d3a40 was a9dc4eb, checked in by smk78, 10 years ago | |
---|---|
|
|
File size: 1.8 KB |
SLD Calculator Tool
Description
The neutron scattering length density (SLD) is defined as
SLD = (b_c1 + b_c2 + ... + b_cn) / Vm
where b_ci is the bound coherent scattering length of ith of n atoms in a molecule with the molecular volume Vm
Specifying the Compound Name
To calculate scattering length densities enter the empirical formula of a compound and its mass density and click "Calculate".
Entering a wavelength value is optional (a default value of 6.0 Å will be used).
TIPS!
- Formula strings consist of atoms and the number of them, such as "CaCO3+6H2O".
- Groups can be separated by '+' or space, so "CaCO3 6H2O" works as well.
- Groups can be defined using parentheses, such as "CaCO3(H2O)6".
- Parentheses can be nested, such as "(CaCO3(H2O)6)1".
- Isotopes are represented by their atomic number in square brackets, such as "CaCO[18]3+6H2O", H[1], or H[2].
- Numbers of atoms can be integer or decimal, such as "CaCO3+(3HO0.5)2".
- The SLD of mixtures can be calculated as well. For example, for a 70-30 mixture of H2O/D2O write "H14O7+D6O3" or more simply "H7D3O5" (i.e. this says 7 hydrogens, 3 deuteriums, and 5 oxygens) and enter a mass density calculated on the percentages of H2O and D2O.
- Type "C[13]6 H[2]12 O[18]6" for C(13)6H(2)12O(18)6 (6 Carbon-13 atoms, 12 deuterium atoms, and 6 Oxygen-18 atoms).
Note
This help document was last changed by Steve King, 01May2015
Note: See TracBrowser
for help on using the repository browser.